A method for making an organic light emitting diode (OLED) display panel generally includes forming organic light-emitting materials on a substrate (e.g., a thin film transistor substrate) by vapor deposition. A vapor deposition mask is used during the formation of the organic light-emitting materials on the substrate and the vapor deposition mask is positioned on the substrate. The main film of the vapor deposition mask used in vapor deposition is generally made of a metal. However, since the accuracy of the pattern process on the metal is difficult to control, a main film made of plastic is provided instead.
While the main film made of plastic is patterned, alignment problems of the main film and a metal frame often occur, which cause burrs and particles (debris) in the process. Burrs may cover the pixel area of the display panel and result in dark spot. The particles are generated by the accumulation of carbonized material, and can cause uneven brightness of the OLED display panel. In addition, if the main film absorbs moisture and is scratched, the vapor deposition quality and thus durability of the display panel is lowered.
Therefore, there is room for improvement in the art.